原子量级条件下单晶硅磨削过程中的亚表面损伤

应用分子动力学仿真研究了原子量级条件下磨粒钝圆半径、磨削深度和磨削速度对单晶硅磨削后亚表面损伤层深度的影响.分子动力学仿真结果表明:在磨削深度和磨削速度相同情况下,随着磨粒钝圆半径的减小,损伤层深度和硅原子间势能亦减小.随着磨削深度的增大,损伤层深度和硅原子间势能增大.在磨削深度和磨粒钝圆半径相同的情况下,在20～200 m/s范围内,磨削速度对单晶硅亚表面损伤影响很小,说明分子动力学仿真对磨削速度的变化不敏感,因此可以适当提高仿真速度,从而缩短仿真时间和扩大仿真规模.单晶硅亚表面损伤主要是基于硅原子间势能的变化,并通过超精密磨削实验进行了实验验证.

Subsurface Damage in the Monocrystal Silicon Grinding on Atomic Scale

A molecular dynamics (MD) simulation is carried out to analyze the effect of cutting edge radius,cut-depth,and grinding speed on the depth of subsurface damage layers in monocrystal silicon grinding processes on an atomic scale.The results show that when the cutting edge radius decreases in the nanometric grinding process with the same cut-depth and grinding speed,the depth of the damage layers and the potential energy between the silicon atoms decrease too.Also,when the cut depth increases,both the depth of the damage layers and the potential energy between silicon atoms increase.When the grinding speed is between 20 and 200m/s,the depth of the damage layers does not change much with the increase of the grinding speed under the same cutting edge radius and cut depth conditions.This means that the MD simulation is not sensitive to changes in the grinding speed,and thus increasing the grinding speed properly can shorten the simulation time and enlarge the simulation scale.In conclusion,the subsurface damage of monocrystal silicon is mainly based on the change of the potential energy between silicon atoms,which is verified by the ultra-precision grinding and CMP experiments.